Finite element investigation of granular dynamics in a split-bottom shear cell

- The wide shear band in split-bottom shear cell is studied via Eulerian finite element method.
- Various banding patterns are satisfactorily reproduced using the numerical model.
- The predictions of band geometry agree well with previous measurements.
- The formation of band depends strongly on rotational speed and material dilation.

Dense granular flow can exhibit various unique behaviours as compared to those of common solids, liquids and gases, an example being the banding phenomenon occurring in sheared granular materials. The shear band is universal in various granular systems and represents a significant challenge in physics. Using a continuum-based Eulerian finite element method, this paper presents an investigation of the wide band phenomenon of granular material within a rotating split-bottom shear cell. It is shown that different patterns and geometrical profiles of the band observed in previous experiments can be well reproduced. The ratio of filling height to split radius is found to control both the band transition and band geometry. A parametric study shows that the obtained band varies remarkably with the rotational rate of shear cell and dilation of granular material, indicating the importance of inertial effect and dilation in the band formation and thus, the necessity of a dynamic modelling approach. The effects of other material properties including the internal friction angle and cohesion are also examined.

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